A prototype touchscreen on show at the Computer Human Interaction (CHI) conference in Vancouver can change from slippery to sticky depending on what's happening on the screen.

A prototype touchscreen on show at the Computer Human Interaction (CHI) conference in Vancouver can change from slippery to sticky depending on what's happening on the screen.

For example, the screen can feel slippery to the touch when a user is dragging a file folder and then feel sticky once the file lands on its destination.

"That allows us to make the interfaces feel more real," said Vincent Levesque, a post-doctoral fellow at the University of British Columbia. "You can feel clicks and you can feel resistance so it feels like you are more engaged with the task and the interface."

The screen uses technology that is different from the haptic feedback sometimes used in smartphones. With haptic feedback, users feel the screen vibrate. Users of the prototype screen feel their fingers pushed away from the screen, rather than feeling a vibration.

"It's a bit like an air hockey table," Levesque said.

The prototype screen is only a few inches diagonally, but it's housed in a relatively large case. The screen also uses lasers to determine the position of the finger. As the team develops the project further, they would like to make the entire device smaller and replace the lasers with capacitive sensing.